What I do in a situation where I can't find something new to write, I write something old. Being a consultant, I have a boatload of old shell scripts I regularly have used, so I have been slowly writting Perl version.

I also used to have the strange habit of finding things to work on while I bombarded with work, but couldn't think of anything to do when I didn't have work. After the last time this happened, I started to keep a list of projects, scripts, books, articles, or other things I really needed to look into in more detail. This has provided me with a never ending list of things to do. It does get a little intimidating when going over the list, but after keeping continually busy for a long time, I've been very happy with the results.